rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=6924/1/0x4000000000000000 softirq=48447/48448 fqs=2 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3640/1:b..l (detected by 1, t=10502 jiffies, g=78037, q=498 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 12104 Comm: kworker/u4:7 Not tainted 6.0.0-rc3-syzkaller-00363-g7726d4c3e60b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Workqueue: bat_events batadv_nc_worker RIP: 0010:rcu_rdp_cpu_online kernel/rcu/tree.c:234 [inline] RIP: 0010:rcu_lockdep_current_cpu_online kernel/rcu/tree.c:773 [inline] RIP: 0010:rcu_lockdep_current_cpu_online+0x83/0x140 kernel/rcu/tree.c:757 Code: 3c 02 00 0f 85 a4 00 00 00 48 03 1c ed e0 b8 a1 8b 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 20 48 89 fa 48 c1 ea 03 80 3c 02 00 <0f> 85 87 00 00 00 48 8d 7b 18 48 8b 6b 20 48 b8 00 00 00 00 00 fc RSP: 0018:ffffc90000007de8 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff8880b9a3aec0 RCX: 0000000000000000 RDX: 1ffff110173475dc RSI: 0000000000010003 RDI: ffff8880b9a3aee0 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: ffff8880b9a2a540 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e823000 CR3: 0000000078aa2000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:112 [inline] rcu_read_lock_held_common kernel/rcu/update.c:102 [inline] rcu_read_lock_sched_held+0x25/0x70 kernel/rcu/update.c:123 trace_hrtimer_start include/trace/events/timer.h:198 [inline] debug_activate kernel/time/hrtimer.c:476 [inline] enqueue_hrtimer+0x2b8/0x3e0 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1702 [inline] __hrtimer_run_queues+0xaf3/0xe40 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:lock_acquire+0x1ef/0x570 kernel/locking/lockdep.c:5634 Code: cf a3 7e 83 f8 01 0f 85 e8 02 00 00 9c 58 f6 c4 02 0f 85 fb 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90004c5fb28 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff9200098bf67 RCX: 9a999f285ce34401 RDX: 1ffff11004552d6e RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff908dc947 R10: fffffbfff211b928 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8bf86880 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:280 [inline] rcu_read_lock include/linux/rcupdate.h:706 [inline] batadv_nc_process_nc_paths.part.0+0xec/0x3c0 net/batman-adv/network-coding.c:687 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:679 [inline] batadv_nc_worker+0xc46/0xfa0 net/batman-adv/network-coding.c:728 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 task:syz-executor.3 state:R running task stack:24008 pid: 3640 ppid: 3630 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5182 [inline] __schedule+0xadf/0x52b0 kernel/sched/core.c:6494 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6806 irqentry_exit+0x31/0x80 kernel/entry/common.c:428 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x4/0x20 kernel/kcov.c:303 Code: 00 00 00 00 00 90 48 8b 0c 24 89 f2 89 fe bf 05 00 00 00 e9 9e fe ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 8b 0c 24 <48> 89 f2 48 89 fe bf 07 00 00 00 e9 7c fe ff ff 66 66 2e 0f 1f 84 RSP: 0018:ffffc900031a7d38 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff88807147ce78 RCX: ffffffff81dbd960 RDX: ffff888079f82100 RSI: ffff88807147ce78 RDI: 0000000000000000 RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000094d114df R13: 000000000000000c R14: ffff888071787db8 R15: 0000000000000000 __d_lookup+0x140/0x460 fs/dcache.c:2483 d_lookup+0xd8/0x170 fs/dcache.c:2430 lookup_dcache+0x1e/0x130 fs/namei.c:1563 __lookup_hash+0x29/0x180 fs/namei.c:1586 do_unlinkat+0x284/0x650 fs/namei.c:4281 __do_sys_unlink fs/namei.c:4345 [inline] __se_sys_unlink fs/namei.c:4343 [inline] __x64_sys_unlink+0xc6/0x110 fs/namei.c:4343 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f9927888bb7 RSP: 002b:00007fff9936f848 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9927888bb7 RDX: 00007fff9936f880 RSI: 00007fff9936f880 RDI: 00007fff9936f910 RBP: 00007fff9936f910 R08: 0000000000000001 R09: 00007fff9936f6e0 R10: 0000555557051853 R11: 0000000000000206 R12: 00007f99278e242e R13: 00007fff993709d0 R14: 0000555557051810 R15: 00007fff99370a10 rcu: rcu_preempt kthread starved for 10498 jiffies! g78037 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:28928 pid: 16 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5182 [inline] __schedule+0xadf/0x52b0 kernel/sched/core.c:6494 schedule+0xda/0x1b0 kernel/sched/core.c:6570 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1657 rcu_gp_kthread+0x236/0x360 kernel/rcu/tree.c:1854 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 11 Comm: kworker/u4:1 Not tainted 6.0.0-rc3-syzkaller-00363-g7726d4c3e60b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Workqueue: events_unbound toggle_allocation_gate Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x46/0x14f lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x206/0x250 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:514 print_other_cpu_stall kernel/rcu/tree_stall.h:619 [inline] check_cpu_stall kernel/rcu/tree_stall.h:762 [inline] rcu_pending kernel/rcu/tree.c:3660 [inline] rcu_sched_clock_irq+0x2404/0x2530 kernel/rcu/tree.c:2342 update_process_times+0x11a/0x1a0 kernel/time/timer.c:1839 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:243 tick_sched_timer+0xee/0x120 kernel/time/tick-sched.c:1480 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline] RIP: 0010:write_comp_data+0x21/0x90 kernel/kcov.c:229 Code: 84 00 00 00 00 00 0f 1f 00 65 8b 05 99 3a 87 7e 49 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 80 6f 02 00 00 01 ff 00 74 0e 85 f6 74 59 8b 82 bc 15 00 00 85 c0 74 4f 8b RSP: 0018:ffffc9000031f940 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffff8880b9a44fc0 RCX: ffffffff817084d7 RDX: ffff8880121da040 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffed10173489f9 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000001 csd_lock_wait kernel/smp.c:414 [inline] smp_call_function_many_cond+0x5e7/0x1430 kernel/smp.c:988 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1154 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1302 [inline] text_poke_bp_batch+0x233/0x6c0 arch/x86/kernel/alternative.c:1490 text_poke_flush arch/x86/kernel/alternative.c:1660 [inline] text_poke_flush arch/x86/kernel/alternative.c:1657 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1667 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:801 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:811 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:803 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306